JP2018048693A - Linear actuator and linear actuator device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a linear actuator and a linear actuator device, which are easy to process the inside of a motor case, can reduce costs and can prevent a defect that looseness of a screw occurs associated with a temperature change due to the difference in material between the case and components.SOLUTION: A linear actuator comprises a motor part 201 having a hollow rotating shaft 203, an output screw shaft 212 inserted on the axis of the hollow rotating shaft, and a screw nut 211 arranged in the hollow rotating shaft and screwed with the output screw shaft. In the linear actuator, a rotational motion of the hollow rotating shaft is converted to a linear motion of the output screw shaft via the screw nut, the hollow rotating shaft is formed in a stepped structure axially having a small diameter part and a large diameter part, a rotor 202B of the motor part is mounted on the outer peripheral surface of the small diameter part, and the screw nut is arranged concentrically in the large diameter part. Thrust radial bearings 204 are provided concentrically in a case 207 of the motor part for rotatably supporting the outer peripheral surface of the large diameter part of the hollow rotating shaft.SELECTED DRAWING: Figure 2B

Description

  The present invention relates to a linear actuator and a linear actuator device in which a screw nut rotating motor shaft using a ball screw or a sliding screw has a hollow shaft.

Conventionally, as this type of linear actuator, for example, there is one as shown in Japanese Patent Laid-Open No. 2007-032596 (Patent Document 1).
In the conventional linear actuator shown in FIG. 13 of Patent Document 1, the motor unit is provided with a hollow rotary shaft, a rotor attached to the outer periphery of the hollow rotary shaft, and the periphery of the rotor. The hollow rotary shaft rotates with energization. The case portion for housing the motor portion is formed in a square tube shape by a bracket and a bearing housing assembled with the front and rear sides of the stator interposed therebetween, and the opening end is closed by a flange.

  The bearing housing of patent document 1 is comprised by the 1st bearing housing and the 2nd bearing housing. Therefore, since the body is composed of the four parts of the stator, the bracket, the bearing housing A, and the bearing housing B, a step is formed due to the difference in tolerance of each part, and the mounting direction can be restricted. For this reason, in order to solve the problem that it was difficult to have an additional function using the body, the body is made into a case, and the motor part having a hollow rotating shaft is placed in the same case with the stator. And a linear actuator and a linear actuator device that are built in together with a bearing that rotatably supports the hollow rotating shaft and are formed in a sealed structure to improve dustproof and waterproof performance, and improve rigidity and assembly accuracy. Is intended to provide.

JP 2007-032596 A

However, since the technology of Patent Document 1 houses all of the motor unit and the mechanism unit in the case, all of the inside of the case is processed, which increases the cost and makes it difficult to ensure accuracy. There was a problem that the stator of the motor part was dedicated.
Furthermore, in the conventional example of Patent Document 1, as is clear from FIG. 13 of Patent Document 1, the thrust radial bearing is fixed by the step portion of the first bearing housing A and the step portion of the second bearing housing B. ing. In the invention of Patent Document 1, the outer ring of the thrust radial bearing is fixed by the outer ring fixing ring that is screwed into the step portion of the case and the case. Therefore, in addition to the above-described problems, a screw for fixing the outer ring of the thrust radial bearing to the case is processed, which increases the cost. Furthermore, when the case is aluminum and the outer ring fixing ring is iron, there is a risk that the screw may loosen due to a temperature change such as a temperature rise due to a difference in thermal expansion coefficient between the aluminum and iron.

  The present invention has been made paying attention to such a conventional problem, and the machining inside the motor case is easy and the cost can be reduced, and the screw accompanying the temperature change due to the difference in the material of the case and the parts. It is an object of the present invention to provide a linear actuator and a linear actuator device that can prevent a problem that the slack of the wire occurs.

In order to solve the above problems, the present invention is provided with a motor portion having a hollow rotary shaft, an output screw shaft inserted through the axis of the hollow rotary shaft, and the hollow rotary shaft. A screw nut threadedly engaged with the output screw shaft, and converting the rotary motion of the hollow rotary shaft into linear motion of the output screw shaft via the screw nut, and the hollow rotary shaft in the axial direction In the linear actuator formed in a stepped structure having a small diameter portion and a large diameter portion, a rotor of the motor portion is attached to the outer peripheral surface of the small diameter portion, and the screw nut is disposed concentrically in the large diameter portion, A bearing that rotatably supports the outer peripheral surface of the large-diameter portion of the hollow rotating shaft is provided concentrically in the case of the motor unit, and a thrust radial bearing that receives both thrust load and radial load is provided on the bearing, The outer race of the thrust radial bearing, and the stepped portion in the radial direction provided in the inner peripheral surface of the case, lies in the axially fixed by a locking member arranged in the axial end surface of the thrust radial bearing.
Further, the present invention provides a bracket disposed at the opening end of the case, a stator of the motor unit disposed between the bracket and the case, and a bolt that fixes the case in the axial direction. The thrust bearing for fixing the thrust bearing is to be fastened together.
Furthermore, the present invention provides a guide portion on the outer surface of the case along the direction of linear movement of the output screw shaft, a moving element that slides along the guide portion, and the moving element for the output. It is connected to the screw shaft.
Still further, the present invention provides a guide hole in the case along the direction of linear movement of the output screw shaft, a guide shaft inserted into the guide hole, and the guide shaft as described above. It is connected to the output end of the screw shaft for output.
Further, the present invention includes the linear actuator according to claim 1 and a guide unit assembled to the linear actuator, and the guide unit includes a moving element coupled to an output screw shaft of the linear actuator. And a guide rail on which the moving element travels, and the moving element linearly moves along the guide rail in conjunction with the movement of the output screw shaft of the linear actuator.
Furthermore, the present invention is configured such that the case of the motor portion of the linear actuator according to claim 1 can be selected, and the type of the case is changed according to the application and is assembled to the motor portion. .

According to the present invention, the outer ring of the thrust radial bearing is fastened in the axial direction by fastening the stepped portion radially processed on the inner peripheral surface of the case and the locking member disposed on the axial end surface of the thrust radial bearing. It is fixed. Therefore, it is easy to assemble at low cost and can be firmly attached.
According to the present invention, the bracket disposed at the opening end of the case, the stator of the motor unit disposed between the bracket and the case, and the bolt that fixes the case in the axial direction. As a result, the thrust bearing for fixing the thrust bearing is integrally fastened, so that it is not necessary to perform screw processing for fixing the outer ring of the thrust bearing to the case, and the cost can be reduced.
Further, according to the present invention, a guide portion is provided on the outer surface of the case along the direction of linear motion of the output screw shaft, and a slider that slides along the guide portion is provided. Since it is connected to the output screw shaft, the guide mechanism is directly assembled to the case, which is advantageous in terms of accuracy.
Furthermore, according to the present invention, a guide hole is provided in the case along the direction of linear movement of the output screw shaft, a guide shaft inserted into the guide hole is provided, and the guide shaft is provided. Is connected to the output end of the screw shaft for output, so that the guide mechanism is directly assembled to the case, which is advantageous in terms of accuracy, and the motor assembly part and the linear motion mechanism assembly part of the case are assembled on the basis of the case. Therefore, it is easy to ensure accuracy.
According to the present invention, the linear actuator according to claim 1 and a guide unit assembled to the linear actuator are provided, and the guide unit is coupled to an output screw shaft of the linear actuator. A movable body and a guide rail on which the movable body travels, and the movable body linearly moves along the guide rail in conjunction with the movement of the output screw shaft of the linear actuator. Can be attached to various mechanisms to perform reciprocating operation.
Further, according to the present invention, the case of the motor part of the linear actuator according to claim 1 is configured to be selectable, the type of the case is changed according to the application, and the case is assembled to the motor part. The case can be selectively attached and used for various applications.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a guideless linear actuator that is a first embodiment of a linear actuator of the present invention. It is a front view of the linear actuator of FIG. It is a BB line sectional view of Drawing 2A. It is a figure of the same part as FIG. 2A. It is the DD sectional view taken on the line of FIG. 2C. It is the E section partial enlarged view of FIG. 2D. It is a disassembled perspective view of the linear actuator of FIG. It is a front view which shows the rod-type linear actuator which is 2nd embodiment of the linear actuator of this invention. It is the FF sectional view taken on the line of FIG. 4A. It is a disassembled perspective view which shows the rod type linear actuator which is 2nd embodiment of the linear actuator of this invention. It is a front view which shows the linear actuator with a single guide which is 3rd embodiment of the linear actuator of this invention. It is the GG sectional view taken on the line of FIG. 6A. It is a perspective view which shows the linear actuator with a twin guide which is 4th embodiment of the linear actuator of this invention. It is a perspective view which shows the linear actuator with a side guide which is 5th embodiment of the linear actuator of this invention. 4A and 4B show the mounting of the linear actuator of the present invention, where (a) is a front view, (b) is a plan view, (c) is a bottom view, (d) is a left side view, (E) is a right side view. FIG. 2 is a perspective view of a state where a guide unit is assembled to the linear actuator of FIG. 1. It is a perspective view which shows five types of linear actuators and each case. It is a front view which shows the rod type linear actuator shown in FIG. 4 with an encoder. It is the HH sectional view taken on the line of FIG. 12A. It is a front view which shows the rod type linear actuator shown in FIG. 4 with an electromagnetic brake. It is the II sectional view taken on the line of FIG. 13A. It is a front view showing a body set screw type rod type linear actuator.

[First embodiment]
Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings.
In FIG. 1 to FIG. 3, reference numeral 200 denotes a linear actuator, and this linear actuator 200 includes an integral rectangular tube case 207 constituting a body, a motor unit 201, a bracket 208, and a flange 209.
The motor unit 201 includes a hollow rotary shaft 203, a rotor 202B attached to the outer peripheral surface of the rotary shaft 203, and a stator 202A provided around the rotor 202B. The motor unit 201 is connected to a drive device (not shown), and is energized by the operation of the drive device to generate a rotating magnetic field.

  The hollow rotating shaft 203 is supported by a small diameter portion 203A supported by a ball bearing 205 supported by a bracket 208 as a normal bearing and a thrust radial bearing 204 as a bearing that receives both a thrust load and a radial load. It has a stepped structure including a large diameter portion 203B. The hollow rotary shaft 203 has the rotor 202B attached to the outer peripheral surface of the small diameter portion 203A, and a ball screw nut 211 described later is disposed in the large diameter portion 203B. The inner ring 204A of the thrust radial bearing 204 is fixed to the large-diameter portion 203B by a lock nut 206 that is screwed into the step portion 203Ba on the outer peripheral surface of the large-diameter portion 203B and the screw portion 203Bb on the outer peripheral surface of the end portion. Yes.

  The square cylindrical case 207 has a stepped inner peripheral portion, and the outer ring 204B of the thrust radial bearing 204 is fixed to a step portion 207A of the inner peripheral portion of the case 207 and a thrust radial bearing as a locking member. It is fixed by the ring 215. As shown in FIG. 2D, the thrust radial bearing fixing ring 215 is fastened by a motor assembly bolt 222 that penetrates the bracket 208, the stator 202A, and the case 207. That is, by fastening the four motor assembly bolts 222 and the thrust radial bearing fixing ring 215, the bracket 208, the stator 202A, the case 207, and the outer ring 204B of the thrust radial bearing 204 are fixed.

  In order to fix the thrust radial bearing 204, the thrust radial bearing 204 must protrude outward in the axial direction from the bearing housing portion of the case 207. The L dimension in FIG. 2E represents the situation. The L dimension is preferably about 20 to 0.01 mm of the axial length L2 of the thrust radial bearing 204. However, it is necessary to secure the dimensions by calculating the coefficient of expansion of the bearing material and the case material due to temperature changes so that the gap L is not lost. In addition, the thrust radial bearing fixing ring 215 needs to be fastened within plastic deformation when fastened by the motor assembly bolt 222.

  As described above, since the stator 202A and the hollow rotary shaft 203, the rotor 202B, and the case 207 are fixed, the hollow rotary shaft 203 is rotated by energizing a stator winding (not shown). Rotates with 202B.

A ball screw shaft / output shaft 212 is inserted through the hollow portion of the hollow rotary shaft 203 on the axis, and the large diameter portion 203B of the rotary shaft 203 is screwed to the ball screw shaft / output shaft 212. A ball screw nut 211 is disposed. The ball screw nut 211 has a flange portion 211A that protrudes radially outward from the opening end of the rotary shaft 203 on the large diameter portion 203B side, and this flange portion 211A is fixed to the lock nut 206 via a ball screw nut fastening screw 214. Has been. Therefore, the ball screw nut 211 can rotate together with the hollow rotating shaft 203.
The ball screw shaft / output shaft 212 is screwed to the ball screw nut 211 and is fixed to a linear motion mechanism (not shown) to prevent rotation, and linearly moves in the left-right direction as the ball screw nut 211 rotates. That is, according to this linear actuator, the rotational motion of the hollow rotary shaft 203 is converted into the linear motion of the ball screw / output shaft 212. The set collar 210 prevents the ball screw shaft / output shaft 212 from being pulled in, and the adjustment knob 213 manually rotates the hollow rotary shaft 203 to manually adjust the position of the ball screw shaft / output shaft 212. Can do.

The operation of the linear actuator 200 of the first embodiment will be described.
When the hollow rotating shaft 203 is rotated by the operation of the motor unit 201, the ball screw nut 211 is also rotated with the rotation of the hollow rotating shaft 203. As the ball screw nut 211 rotates, the ball screw / output shaft 212 starts moving in the axial direction. When the hollow rotary shaft 203 is rotated in the reverse direction, the output screw shaft 212 starts moving in the reverse direction. Thus, by switching the rotation direction of the hollow rotating shaft 203, the ball screw / output shaft 212 starts reciprocating.

  Since the linear actuator 200 is composed of an integrated case 207 housing the motor unit 201 and the linear motion mechanism, the motor unit 201 can be changed to ones having different characteristics while maintaining rigidity. Further, the fastening portion of the square cylindrical case 207 with the motor portion 201 needs to be processed to ensure accuracy, but the inner peripheral cylindrical portion is processed to form a radial step on the inner peripheral surface. Since only one step of inner circumference processing is required, processing can be performed at low cost. Furthermore, since the mounting screw hole 207a can be provided directly in the case 207 when assembling to a device or the like, the case 207 can be attached in close contact with the mounting portion, and assembling is easy, and Can be firmly attached. Furthermore, the bracket 207 </ b> A is fastened in the axial direction by a stepped portion 207 </ b> A processed radially on the inner peripheral surface of the case 207 and a fixing ring 215 (locking member) disposed on the axial end surface of the thrust radial bearing 204. 208, the stator 202A, the case 207, and the outer ring 204B of the thrust radial bearing 204 are fixed. Therefore, the thrust radial bearing 204 can be easily assembled at low cost, and the thrust radial bearing 204 can be firmly attached.

[Second Embodiment]
4 and 5 show a second embodiment of the present invention, in which the outer shape of a rectangular tube-like case is formed thin. In the second embodiment, the same parts as those in FIGS. 1 to 3 are denoted by the same reference numerals, and the description of the same parts is omitted.
4 and 5 show an example of a linear actuator 300 with a round shaft in which a case 307 is provided with a guide 307A of a round shaft.
In this embodiment, a case 307 used in place of the case 207 of the first embodiment is provided with portions 307a and 307b for accommodating the linear bush 317 and the linear shaft 316 for guiding the linear motion. It is. The tip of the linear shaft 316 is fastened to the fastening joint 319 with a screw 320, and the tip of the ball screw / output shaft 312 is fastened to the fastening joint 319 with a screw 321. The ball screw / output shaft 312 is prevented from rotating by the linear shaft 316 guided by the shaft guide 307A, and linearly moves in the left-right direction as the ball screw nut 311 rotates.
Although the example in which the shaft guide 307A by the linear bush 317 and the linear shaft 316 is provided at two locations on both side surfaces of the case 307 is shown, the shaft guide 307A may be provided at one location on one side of the side surface.
In the second embodiment, the same effect as that of the first embodiment can be obtained.

[Third embodiment]
6A and 6B show a third embodiment of the present invention, which shows the structure of a linear actuator provided with a linear guide mechanism of a single guide block. In the third embodiment, a guide mechanism is assembled outside the linear actuator shown in FIG. Here, the structure of the guide mechanism of the linear actuator 400 will be described.
The case 407 is provided with a guide rail mounting portion 407A, and the guide rail 408 is assembled with screws 420. A guide block 409 moves along the guide rail 408. A table 410 as a mover is coupled to the guide block 409, and a joint portion 410 a bent downward is provided at the tip of the table 410. A tip of a ball screw / output shaft 412 is fastened to the joint portion 410 a with a screw 421. When the ball screw / output shaft 412 moves, the table 410 and the guide block 409 move synchronously via the joint portion 410a. The configuration of the ball screw / output shaft 412 is the same as that described in the embodiment of FIGS.
In the third embodiment, the same effect as that of the first embodiment can be obtained.

[Fourth embodiment]
FIG. 7 is a modification of FIG. 6 and shows the structure of a case 507 that fastens guide rails 508A and 508B to the upper end surfaces of the mechanism and motor 501. FIG. Since the mechanism part of the linear actuator 500 of the fourth embodiment is the same as that described in the embodiment of FIGS. 4 and 5, description of the mechanism part will be omitted.
The configuration of the case 507 is the same as that of the embodiment of FIG.
In this case, the case 507 is provided with guide rails 508A and 508B on the upper surface of the portion where the left and right round shaft guides are provided, and a table 510 as a mover guided along the guide rails 508A and 508B is provided in the case 507. Arranged on the top surface. Guide blocks 509A and 509B are provided on the left and right inner sides of the table 510, and the guide blocks 509A and 509B are configured to slide along the guide rails 508A and 508B. A joint 510a bent downward is provided at the tip of the table 510, and this joint 510a is connected to the tips of the ball screw / output shaft 312 and the linear shaft 316 described in FIG. .
Since the guide blocks 509A and 509B sliding with the respective guide rails 508A and 508B are provided on the table 510, the guide blocks 509A and 509B are linearly moved according to the movement of the ball screw / output shaft 312. This is a type in which the guide of the actuator of FIG.
In the fourth embodiment, the same effect as that of the first embodiment can be obtained.

[Fifth embodiment]
FIG. 8 is a modified example of FIG. 7 and shows a structure using a case 607 to which a guide rail 608 and a guide block 609 can be attached on the side surface of the mechanism portion and the motor 601. This is an actuator that suppresses the height of the table as a movable element. Since the mechanism part of the linear actuator 600 of the fifth embodiment is the same as the structure described in the embodiment of FIGS. 1 to 3, the description of the mechanism part will be omitted.
A case 607 is integrally provided on the side surface of the mechanism and motor unit 601 along the longitudinal direction of the mechanism and motor unit 601, and a guide rail 608 is provided on the upper surface of the case 607 along the longitudinal direction. ing.
The guide block 609 is fastened to the lower surface of a table 610 as a moving element, and a joint portion 610a extending downward is provided at the tip of the table 610. The joint portion 610a has a lateral direction, that is, a mechanism portion and a motor. An extension portion 610 b extending toward the portion 601 is fastened to the tip of the ball screw / output shaft 612. The ball screw / output shaft 612 is linearly operated by the movement of the motor unit 601, and the table 610 is linearly moved in conjunction with this.
Also in the fifth embodiment, the same effects as in the first embodiment can be obtained.

As described above, the case of the actuator shown in FIGS. 4 to 8 is changed according to the guide for guiding the linear motion. This is an actuator that draws out the features and functions of each guide.
In this case, the motor part and the guide fastening part need to be processed to ensure accuracy. However, since the processing is performed in an integrated case, there is no error due to the assembly as compared with the case where the motor portion and the guide portion are separated, and the assembly can be performed with high accuracy.

  FIG. 9 is a diagram illustrating attachment of the actuator of FIG. As shown to Fig.9 (a), it has a structure which can be attached in A surface, B surface, and C surface. As shown in FIG. 9C, a tap 307a is processed on the A surface and can be fastened and fixed to the A surface with screws. A pin hole 307aa for positioning reproducibility is also machined on the A surface. As shown in FIG. 9 (b), the A surface is attached to the D surface with four holes 307d penetrating to the A surface, and the A surface is fastened and fixed from the D surface to the fool hole 307d with screws. I can do it. On the B surface, as shown in FIG. 9D, four taps 309a are processed on the flange 309 and can be fastened and fixed by screws. As shown in FIG. 9 (e), taps 307 c are formed in the case 307 at four locations on the C surface, and the case 307 can be fastened and fixed. Thus, the actuator can be fixedly fastened from the direction of the actuator 3.

[Sixth embodiment]
FIG. 10 shows a combination of the linear actuator 200 of FIG. 1 and a guide unit 801.
Since the mechanism part of the linear actuator 200 of the sixth embodiment is the same as the structure described in the embodiment of FIGS. 1 to 3, the description of the mechanism part will be omitted.
The linear actuator 200 alone cannot be operated directly unless the ball screw / output shaft 212 is stopped. Further, since the guide is necessary when actually used from load conveyance or the like, the mechanism of the guide unit 801 shown in FIG. 10 is necessary.
The guide unit 801 includes an actuator mounting flange 802 that is mounted on the flange 209 of the linear actuator 200 via an actuator mounting screw 807, a guide rail mounting base 803 that is mounted orthogonal to the actuator mounting flange 802, and a guide rail mounting base. A guide rail 804 fixed to the upper surface of 803, a pair of guide blocks 805 slidably assembled to side rail portions 804a on both sides of the guide rail 804, and a table 806 on which these guide blocks 805 are attached to the lower surface, It consists of The table 806 is screwed to the ball screw / output shaft 212 via a ball screw shaft fastening screw 808. The guide rail 804 is attached to a guide rail attachment base 803 via guide rail attachment screws 810. The table 806 is fastened to the guide block 805 with a table mounting screw 809.
When the ball screw / output shaft 212 linearly moves, the table 806 linearly moves in synchronization with the guide rail 804.

FIG. 11 shows the linear actuator shown in FIGS. 1 to 8 and the respective cases attached to the motor unit.
FIG. 11A shows the linear actuator 200 and the case 207 described in the embodiment of FIGS. 1 to 3.
FIG. 11B shows the linear actuator 400 and the case 407 described in the embodiment of FIGS. 6A and 6B.
FIG. 11C shows the linear actuator 300 and the case 307 described in the embodiment of FIGS. 4 and 5.
FIG. 11D shows the linear actuator 500 and the case 507 described in the embodiment of FIG.
FIG. 11E shows the linear actuator 600 and the case 607 described in the embodiment of FIG.
By changing the shape of the case, it can be changed to an actuator with or without a guide.
Also, with a guide, depending on the type of guide, the case to which it is attached can be changed to make a linear actuator with a different purpose.
In addition to those shown in FIG. 11, the structure of the motor part, the ball screw / nut and its bearing part is not changed, and the actuator can be changed to various purposes by changing the type of the case and the guide attached thereto.

12 to 14 show application examples of the present invention.
12A and 12B are obtained by assembling a motor rotation detection sensor 331 to the linear actuator shown in FIGS. 4A and 4B.
13 (A) and 13 (B) are applied to the linear actuator shown in FIGS. 4 (A) and 4 (B) with an additional function of a motor such as a rotating electromagnetic brake 332. Is.
Needless to say, the rotation detection sensor can cope with various methods such as optical, magnetic, and mechanical methods. Needless to say, the electromagnetic brake can be applied to the non-excitation operation type and the excitation operation type.

FIG. 14 is a modification of FIG. 5 and shows an example in which a motor assembly bolt 322B is assembled in place of the motor assembly bolt 222 with a screw head disposed on the thrust / radial bearing fixing ring 315B side. The same parts as those in FIG. 5 are denoted by the same reference numerals, and description of the same parts is omitted.
In this case, the thrust / radial bearing fixing ring 315B is a through-hole for passing a screw, and the bracket 308B is processed with a tap. In the example of FIG. 5, since the bracket 308 side is assembled with the screw head, the bracket 308 is tapped and fixed with screws through a through hole and a thrust / radial bearing fixing ring 215 side.
From this, the fixing direction of the screw and FIGS. 5 and 14 can be selected, and the same effect can be obtained.

As described above, according to the above embodiment, the effects listed below can be obtained.
The bracket 208 is fixed by fastening the stepped portion 207A radially processed on the inner peripheral surface of the case 207 and the locking member (fixing ring 215) disposed on the axial end surface of the thrust radial bearing 204 in the axial direction. The child 202A, the case 207, and the outer ring 204B of the thrust radial bearing 204 are fixed. Therefore, the thrust radial bearing 204 can be easily assembled at low cost, and the thrust radial bearing 204 can be firmly attached.
As shown in FIG. 11, the motor unit 201, the ball screw shaft / output shaft 212, and the linear motion mechanism of the bearing unit thereof are not changed, but the case 207 and the guide mechanism unit can be changed to be changed to an actuator having a different use and purpose. .
Since the guide mechanism is directly assembled to the case 207, accuracy is advantageous.
Since the motor assembly part and the linear motion mechanism assembly part of the case 207 are assembled on the basis of the case, it is easy to ensure accuracy.
Since the case 207 and the like have a short L dimension from the flange mounting surface to the stator mounting surface, it is easy to ensure accuracy during processing.
A mounting hole can be provided in the case 207, and the mounting surface can be increased as necessary.
The motor unit 201, the case 207, the bracket 208, and the hollow rotary shaft 203 employ a thrust / radial bearing fixing ring 215 and are assembled with four assembly screws 222. Can be changed. Further, it is not necessary to perform screw processing on the cylindrical inner peripheral portion of the case.

  The present invention is not limited to the above embodiment. For example, as shown in FIG. 11, the combination of the motor unit 201 and the ball screw shaft / output shaft 212 is not limited to that shown in FIG. Various combinations or applications are possible. In addition, it goes without saying that the present invention can be appropriately modified and implemented within the scope not changing the technical scope of the present invention.

200, 300, 400, 500, 600 Linear actuator 201 Motor unit 202A Stator 202B Rotor 203, Hollow rotating shaft 204 Thrust radial bearing 205 Ball bearing 206 Lock nut 207, 307, 407, 507, 607 Case 307A Guide 208 Bracket

211 Ball screw nut 212, 312 Ball screw / output shaft 215 Thrustal bearing fixing ring 222 Motor assembly bolt 316 Linear shaft 319 Fastening joint portion 407A Guide rail mounting portion

Claims (6)

A motor unit having a hollow rotary shaft; an output screw shaft inserted through an axis of the hollow rotary shaft; and a screw nut disposed in the hollow rotary shaft and screwed into the output screw shaft. A step having a small-diameter portion and a large-diameter portion in the axial direction of the hollow rotary shaft, and converting the rotary motion of the hollow rotary shaft into a linear motion of the output screw shaft via the screw nut. In the linear actuator formed in the structure, the rotor of the motor part is attached to the outer peripheral surface of the small diameter part, and the screw nut is disposed concentrically in the large diameter part,
A bearing that rotatably supports the outer peripheral surface of the large-diameter portion of the hollow rotating shaft is provided concentrically in the case of the motor unit, and a thrust radial bearing that receives both a thrust load and a radial load is provided on the bearing, A linear actuator in which an outer ring of a thrust radial bearing is fixed in an axial direction by a radial step provided on the inner peripheral surface of the case and a locking member disposed on an axial end surface of the thrust radial bearing. .   For fixing the thrust radial bearing by a bracket disposed at the opening end of the case, a stator of the motor unit disposed between the bracket and the case, and a bolt for axially fixing the case. The linear actuator according to claim 1, wherein the locking member is integrally fastened.   A guide portion is provided on the outer surface of the case along the direction of linear movement of the output screw shaft, a mover that slides along the guide portion is provided, and the mover is connected to the output screw shaft. The linear actuator according to claim 1 or 2.   A guide hole is provided in the case along the direction of linear movement of the output screw shaft, a guide shaft inserted into the guide hole is provided, and the guide shaft is connected to an output end of the output screw shaft. The linear actuator according to claim 2, wherein the linear actuator is connected to the linear actuator.   The linear actuator according to claim 1, and a guide unit assembled to the linear actuator, wherein the guide unit includes a mover coupled to an output screw shaft of the linear actuator, and the mover includes A linear actuator device comprising: a traveling guide rail, wherein the moving element linearly moves along the guide rail in conjunction with the movement of the output screw shaft of the linear actuator.   The linear actuator device according to claim 1, wherein the case of the motor portion of the linear actuator according to claim 1 is configured to be selectable, and the type of the case is changed according to the application and is assembled to the motor portion.

Images